If you're on a road trip and find that you forgot your car charger for your phone or other USB device, Popular Science shows off how to make one on the fly using a USB cable and any 5-volt car cigarette lighter adapter.

The process is incredibly simple, but you still want to make sure you do it right so you don't blow up your phone. All you need to do is cut the USB cable, and strip the insulation to reveal a red and black wire. Do the same to the 5-volt cigarette lighter adapter (don't use a higher voltage). Finally, twist the black wires together, then the red, and wrap some tape around them to insulate them. When you're done, you've created an emergency car charger that works just as well as anything you'd purchase at a store. Car chargers aren't particularly expensive, but if you're out in the middle of nowhere and need a quick fix, this works great.